Simultaneous Removal Of Dye And Heavy Metals By Burkholderia Vietnamiensis C09V

Dye and heavy metals were often used in various industrial applications. Since the residues of dye and heavy metal release into the environment, they result in complicated compositions and degradation-resistant in wastewater. Thus, the wastewater containing dye and heavy metal cause environmental problem and attracts the public concerns. Therefore, the removal of dye and metal from wastewater has been received a great attention. Since Crystal violet with the high content of Cu and Cr are often are used in dyeing process simultaneous removal of crystal violet and metal ions such as Cu and Cr is a challenge to develop the remediation techniques. In this study, the experiments were first conducted to remove crystal violet and Cu2+simultaneously by Burkholderia vietnamiensis C09V, which is based on our previous work. The results indicates that the highest removal rate of 60 mg/L crystal violet and 50 mg/L Cu2+were 34.9%and 41.3% at 30℃, pH 5.0 for 42h, respectively. The kinetic of crystal violet corresponded to the pseudo first-order model and the kinetic of Cu2+ was fitted with pseudo second-order model. EDS was used to prove the biosorption process of Cu2+by B. vietnamiensis C09V. The new findings in this study clearly show that B. vietnamiensis C09V can be used for the simultaneous removal of crystal violet and Cu2+. The low removal rate of crystal violet and Cu2+was observed using free cells as shown in last chapter as a consequent study, the B. vietnamiensis C09V was immobilized on PVA-alginate-kaolin to improve the removal ability. Compared with free cells, the removal rate of crystal violet and Cu2+ by immobilized cells were enhanced remarkably, which was 89.4% and 64.1%, respectively. In addition, the removal of Cr (VI) using immobilized cells was also studied since Cr(VI) is anion and also presence in dye efferent. The results show that 92.7%of crystal violet and 64.1% of Cr6+ were removed. The removal of crystal violet and heavy metals (Cu2+, Cr2O72-) were fitted well by pseudo second-order model and the degradation of crystal violet was also satisfied with pseudo first-order model, indicating that crystal violet was adsorbed to the surface of immobilized cells firstly and then degraded by the cells inside the pellets, while heavy (Cu2+, Cr2O72-) metals were only removed by biosorption process. Characterization of SEM, EDS and FTIR shows that B. vietnamiensis C09V could be catched into the interior of pellets and the immobilized cells could remove crystal violet and heavy metals by the functional groups on the surface of the beads. Furthermore, the analysis of XPS was demonstrated that Cr6+ could be reduced to Cr3+ by B. vietnamiensis C09V. The removal rate of crystal violet was still about 80% while the low removal rate of heavy metals when the immobilized cells were reused after 4 cycles. It was suggested that the immobilized cells could be a potential biomaterial for real applications.